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From:   "Ethan D. Twardy" <ethan.twardy@gmail.com>
To:     Miguel Ojeda <ojeda@kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Wedson Almeida Filho <wedsonaf@gmail.com>,
        Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>,
        =?UTF-8?q?Bj=C3=B6rn=20Roy=20Baron?= <bjorn3_gh@protonmail.com>,
        Benno Lossin <benno.lossin@proton.me>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, Miguel Cano <macanroj@gmail.com>,
        Tiago Lam <tiagolam@gmail.com>, Finn Behrens <me@kloenk.de>,
        Kees Cook <keescook@chromium.org>,
        rust-for-linux@vger.kernel.org (open list:RUST),
        linux-kernel@vger.kernel.org (open list),
        llvm@lists.linux.dev (open list:CLANG/LLVM BUILD SUPPORT)
Cc:     "Ethan D. Twardy" <ethan.twardy@gmail.com>,
        Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Subject: [PATCH v3 1/1] scripts/rust_is_available: Fix clang version check
Date:   Tue, 30 May 2023 20:32:11 -0500
Message-Id: <20230531013211.27408-2-ethan.twardy@gmail.com>
In-Reply-To: <20230531013211.27408-1-ethan.twardy@gmail.com>
References: <20230531013211.27408-1-ethan.twardy@gmail.com>
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During out-of-tree builds where the path to the kernel source tree
contains a version string, scripts/rust_is_available.sh incorrectly
identified the version string of libclang to be the version string in
the kernel sources path, resulting in CONFIG_RUST_IS_AVAILABLE
erroneously set to 'n'.

This issue was previously affecting builds on distributions, such as
Gentoo Linux, where the kernel source tree is under version control,
and placed under a path containing the current kernel version string
in /usr/src.

The fix is to take special care to match only the version string
following the string 'clang version' in the output.

To reproduce:

  $ cd ~/build && make -C ~/linux-6.2.0 O=$PWD LLVM=1 rustavailable
  [...]
  *** libclang (used by the Rust bindings generator 'bindgen') is too old.
  ***   Your version:    6.2.0
  ***   Minimum version: 11.0.0
  [...]

Fixes: 78521f3399ab ("scripts: add `rust_is_available.sh`")
Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Tested-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>

diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh
index aebbf1913970..e8a1439be9f8 100755
--- a/scripts/rust_is_available.sh
+++ b/scripts/rust_is_available.sh
@@ -102,8 +102,8 @@ fi
 # Check that the `libclang` used by the Rust bindings generator is suitable.
 bindgen_libclang_version=$( \
 	LC_ALL=C "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang.h 2>&1 >/dev/null \
-		| grep -F 'clang version ' \
-		| grep -oE '[0-9]+\.[0-9]+\.[0-9]+' \
+		| grep -oE 'clang version [0-9]+\.[0-9]+\.[0-9]+' \
+		| cut -d' ' -f3 \
 		| head -n 1 \
 )
 bindgen_libclang_min_version=$($min_tool_version llvm)
-- 
2.40.1